NFC Tags Explained

What are NFC tags ?

As discussed earlier in this section, Near Field Communication (NFC) is a wireless technology that allows the transfer of data such as a web address, text or numbers between two NFC devices. An NFC Tag is one such 'device' and is essentially a small microchip containing a small amount of memory attached to an antenna/aerial which can store a small amount of information for transfer to another device, such as a mobile phone.

NFC tags and NFC products

RapidNFC manufacture and stock a very wide variety of different NFC tags and products. We generally call items like wristbands, keyfobs, pens and so on 'NFC Products' and generally use 'NFC Tags' for stickers and inlays. Read more about the choosing which NFC tag >

What information can you store ?

There's a whole set of different data types you can store on an NFC tag. The actual amount of data varies depending on the type of NFC tag used - different tags have different memory capacities. For example, you may choose to store a URL (web address) or a telephone number.

Usually, this information is stored in a specific data format (NDEF - NFC data exchange format) so that it can be reliably read by most devices and mobile phones.

Could someone change my NFC tag ?

NFC tags can be locked so that once data has been written, it cannot be altered. For most tags this is a one way process so once the tag is locked it cannot be unlocked.
Encoding and locking are two separate actions. NFC tags can be re-encoded numerous times until they are locked.

How can I encode NFC tags ?

Encoding on a small scale is easy to do from your NFC enabled mobile phone. You can download apps, such as NXP's free 'Tag Writer' app for Android, which can get you encoding in minutes. For larger scale encoding, we offer a reliable and timely encoding service to match the requirements of your project.

What batteries do they take ?

That's the clever thing about NFC tags. They don't require batteries. They get their power from just being near a powered NFC device, for example a mobile phone.

How close do I have to be to the tag for it to work?

NFC tags typically operate within three to six centimetres. This close range makes NFC perfect for interaction and means that tags can't 'accidently' be read or used for unwanted tracking.

How can I encode the tags ?

Encoding on a small scale is easy to do from your NFC enabled mobile phone. We provide information on how to encode nfc tags yourself.

How large or small does an NFC tag have to be ?

Most of our tags are between 22mm diameter to 38mm diameter. This is generally an optimum size for the NFC tag. In some instances, such as laundry tags, we might make them smaller but usually the performance (scan distance) tends to reduce. All the tags on the RapidNFC store have been tried and tested to ensure good scan distances. We also released our ScanStrength scan rating system so you can quickly and easily assess the relative scan distances between each type of tag.

NFC tags on metal surfaces

One important thing to consider when purchasing NFC tags is that standard tags won't work directly onto a metal surface. (Directly meaning less than around 0.5 centimetre). In those cases, a special 'on-metal' NFC tag is required. This has a very thin layer of ferrite foil or similar material which effectively creates a 'barrier' between the tag and the metal - allowing it to work.